Product Details
The P28 and P128 Series Lube Oil Controls provide dependable and economical oil pressure cut-out for pressure-lubricated refrigeration compressors. The field-adjustable pressure differential of these controls provides compressor operation according to the manufacturer?s specifications. The P28 and P128 controls operate by measuring the net lube oil pressure and de-energizing the compressor if the pressure falls below the differential setpoint.
Manual or automatic reset models are available with factory set and sealed time delays of 30, 45, 60, 90, or 120 seconds (all time delays may not be available on all models). The P128 is the same control as the P28 but with 1/4 inch male flare pressure connections.
Features and Benefits
Built-in Time Delay Relay with Ambient Compensation: Minimizes timing fluctuations due to temperature variations
Trip-free Manual Reset: Provides manual reset that cannot be overridden by pressing and holding the reset button
Replaceable Time Delay Relay Assembly: Allows easy field replacement of the time delay relay and terminal board
Available with Runlight and Alarm Terminals: Allows the control to be wired for normal oil pressure runlight signals and shutdown alarm circuits for remote monitoring of oil pressure status
Specifications
Adjustable Cut-out Pressure Difference: 8 to 70 psi
Maximum Differential: 70 psi
Maximum Working Pressure: 250 psig (on the high side)
Maximum Overpressure: 325 psi (oil and low side pressure)
The time delay relay is de-energized 3 to 5 psi (21 to 34 kPa) above the cut-out scale setting.
Pressure Switch Units: Enclosed Dust-protected Pennswitch
Ambient Operating Conditions: 32 to 104?F / 0 to 40?C
Mounting: Flat Surface or with a Universal Mounting Bracket (Part No. 271-51)
Wiring Terminal: Large 8-32 x 1/4 in. Binder Head Screws
Dimensions: 5.66 x 5.32 x 2.09 in. / 144 x 135 x 53 mm
📄 Datasheet (Technical Specifications):
Download P28AA-1C Datasheet (PDF)